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Cubase: Detailed Audio Editing

Cubase Tips & Techniques
By Simon Millward

Dragging the Range Selection tool within an audio event allows you to make selections across any range in the Project window.Dragging the Range Selection tool within an audio event allows you to make selections across any range in the Project window.

Cubase SX supplies us with a comprehensive set of editing tools, but the manner in which they can be used varies enormously — and also depends upon the task at hand...

There are probably no hard and fast rules about exactly how you go about doing detailed audio editing in Cubase SX. For example, some audio editing jobs can benefit from the drawing of volume automation curves in the sub-tracks of the Project window. This often suits the removal of unwanted breathing, hum, hiss and other interference within vocal or guitar recordings, or the spill between drum microphones. Automation curves have the advantage of being non-destructive and visually clear on the screen, but they may not be ideally suited to all audio editing tasks.

This month, I propose to show you some techniques for the more 'destructive' type of audio editing — where you go in and actually change the waveform — as well as a lightning-fast non-destructive technique for setting up crossfades within audio events in the Project window.

These techniques help with the removal of clicks and the detailed modification of breaths and other interference within vocal recordings. Before you frown upon my use of the word 'destructive', remember that destructive audio editing in Cubase SX is never truly destructive since you can always go back to the original (or undo the processing steps) in the Offline Process History dialogue.

Preparing Your Work Space

When you are editing audio in fine detail, you might assume that you should simply select the event, open the Sample Editor and use its specialised toolbar. After all, the Sample Editor is for detailed editing at the sample level. While this is true, it is not always the best solution, and you may be overlooking some useful editing techniques along the way. There is a lot you can achieve in the Project window before you ever need to open the Sample Editor. However, before you start any detailed audio editing it's worth taking the time to assemble your own set of essential tools and think why you need them and in what combinations they are particularly useful. These could be the standard tools as you find them on the toolbar, they could be menu functions, or they could be existing key commands or macros.

Tools & Functions For Audio Editing

Tool or FunctionMenu or Toolbar LocationKey Command
Range Selection tool(Project window toolbar)'2'
Zoom To Selection(Edit / Zoom menu)'Z'
Undo Zoom(Edit / Zoom menu)Alt+Z
Play Selection range(Transport menu)Alt+Space
Select None(Edit / Select menu)Alt+\
Fade-out(Audio / Process menu)F5
Silence(Audio / Process menu)F6
Fade-in(Audio / Process menu)F7
Split At Cursor(Edit menu)Alt+X
Crossfade(Audio menu)'X'
Open Focused Sample Editor(Edit / Macros)'W'
Draw tool(Sample Editor toolbar)'3'

If not already assigned, assign appropriate key commands to the menu functions you expect to use most frequently, and, if you regularly use particular combinations of tools and functions, write a macro and assign an appropriate key command to it. Organising key commands and macros helps you use your set of tools quickly and easily.

Set up your Project window with suitable dimensions and an appropriate track size for your audio tracks. This gives you the necessary screen space within which you can work comfortably. Save your settings as a Workspace (Window / Workspaces).

Establish a practical physical method of using your tools. For example, try arranging your work area so that you are using your left hand for key commands on your QWERTY keyboard and your right hand for mouse manipulations (or vice versa for left-handed users). This two-handed approach can dramatically speed up the editing process.

Natural Selection

My own set of essential tools and functions for audio editing is shown in the table on the previous page.

As you can see, the first few items in the list are based around the idea of 'selection'. When I am editing audio in fine detail, I find that I repeatedly need to select a specific passage in order to zoom in to take a better look or to engage playback over that selection alone. For example, when you hear a digital click in your audio the natural reaction is to stop playback, select the area where you heard the click, zoom in to find out if it is possible to see the click in the waveform, and then play back the passage again. This sequence of actions is taken care of with the first four tools/functions in my list. Let's take a look at their use in more detail.

The Range Selection tool is a real friend when it comes to detailed audio editing. By default, this tool is selected by pressing '2' on the computer keyboard, or you can select it directly using the mouse on the toolbar. It's a simple matter to select a range in an audio event in the Project window, by dragging the tool within the event.

The Zoom To Selection function (Edit / Zoom submenu) fills the Project window with the selected audio. This is a good one-step function for instantly focusing on the area of interest. To ensure simultaneous horizontal and vertical zooming deactivate the Enlarge Selected Track function in the Edit menu.The Zoom To Selection function (Edit / Zoom submenu) fills the Project window with the selected audio. This is a good one-step function for instantly focusing on the area of interest. To ensure simultaneous horizontal and vertical zooming deactivate the Enlarge Selected Track function in the Edit menu.Once you have made your selection, the Zoom To Selection function is an excellent way of instantly zooming in to the details of the audio, as it fills the whole of the Project window with the selected passage. By default, the key command for Zoom To Selection is Alt+S, but I have found it easier to re-assign 'Z' to this function. I have also assigned Alt+Z to the Undo Zoom function. This means that you can now instantly zoom in to your selection and back out to an overview of the Project window using the fairly logical 'Z' and Alt+Z key commands.

Once you are zoomed in to your selection, you may wish to engage playback over the chosen passage. This is easy using Play Selection Range in the Transport menu (by default, the key command is Alt+Space). You could also use Alt+G to engage loop playback. When you are viewing short passages of audio at high magnification like this it is normally best to deactivate Autoscroll (press 'F') to prevent the selection scrolling awkwardly out of view. Also of great importance is the Select None function (the fifth item on the list) which allows you to cancel the current selection so you can start afresh with a new selection. This is essential when you need to select a new range which is found within the boundaries of the current selection.

Close To The Edit

Using combinations of the first five tools and functions allows you to navigate to the problem area within your audio. Detailed audio editing is one of the few occasions where it is almost as important to get a good view of the edit as it is to hear it properly. Zoom To Selection should allow you to get close enough to start the actual editing. I do a lot of work with vocals and the spoken voice and the next three functions in my list have been chosen specifically for this. The functions in question, Fade-out, Silence, and Fade-in, are all found in the Process menu and I am using these principally for removing or reducing unwanted breath and lip interference. Of course, the techniques described here can be adapted to any kind of audio material.

Select an appropriate range and use the Fade-out function (Audio / Process menu) to create a suitable fade-out just after the wanted part of the material. Note the low-level interference in between the two main waveforms. This is the target for this processing technique.Select an appropriate range and use the Fade-out function (Audio / Process menu) to create a suitable fade-out just after the wanted part of the material. Note the low-level interference in between the two main waveforms. This is the target for this processing technique.Directly after the fade-out, a second range selection is processed using the Silence function (Audio / Process menu). This range selection begins where the previous range selection for the fade-out ends.Directly after the fade-out, a second range selection is processed using the Silence function (Audio / Process menu). This range selection begins where the previous range selection for the fade-out ends.Directly after the silence, a third range selection is processed using the Fade-in function (Audio / Process menu).  This range selection begins where the previous range selection for the silence ends.Directly after the silence, a third range selection is processed using the Fade-in function (Audio / Process menu). This range selection begins where the previous range selection for the silence ends.As many readers will already be aware, brutally removing all unwanted noises in a vocal recording with the Silence command alone is rarely a satisfactory solution. Sudden changes between background ambience and absolute digital silence stick out like a sore thumb, particularly when the target audio is isolated or high in the mix. The result is wholly unnatural. In addition, complete removal of all breaths can render the performance sterile and lifeless. So, what is the solution? Well, where absolute silence is necessary to remove an unwanted click or lip noise, you normally get far better results by fading down to the edit point, overwriting with an appropriate length of silence, and fading back up to continue with the remaining audio. The Fade-out, Silence and Fade-in functions allow you to do exactly this, and that is why they are in this order in my list. Selecting the Fade-out or Fade-in functions opens dialogues where you can choose a preset fade shape using the buttons below the curve display. Alternatively, you can create your own by dragging the handles which appear when you click on the line of the curve. Each time you select either the Fade-in or Fade-out functions, the dialogue opens with the previously selected curve in the display, which can be quite handy for repetitive editing. The Silence function has no dialogue since it simply replaces any selected audio with absolute silence.

With this technique, the Fade functions are intended to be used in combination with the Range Selection tool which defines the section of audio to be processed. The screens above show this triple-tool technique in action, removing low-level lip and breath noises between words in a voice recording. Note that after selecting and processing the section for the fade-out, selection of the second section intended for the Silence function is achieved by dragging the start point of the first selection over and beyond its end point (wrapping over) to create a new selection. This ensures that your silence starts at the exact end point of the fade-out. A similar technique should be used for the fade-in to ensure that the fade begins at the exact end point of the preceding silent section.

It is also possible to use the Envelope function to achieve similar results in one move by creating your own 'bowl' shaped envelope, but separating the fade and silence functions gives you maximum flexibility when dealing with difficult edits. In all cases, successful results depend very much upon the accuracy of the range selections as well as the appropriateness of the fade curves. Cutting too close to the wanted material might prematurely stifle the outgoing or incoming audio. You also need to pay careful attention to breaths, particularly at the start of a word or phrase. These are often best left untouched to retain the natural feel of the performance.

Secret Weapon

A vocal recording suffering from 'lip-smacking' noises between words, seen as two brief peaks at around 25s and 35s.A vocal recording suffering from 'lip-smacking' noises between words, seen as two brief peaks at around 25s and 35s.The same vocal recording after processing with the Crossfade function technique described in the main text. Where necessary, the crossfades may be fine tuned directly in the Project window by dragging the whole crossfade to a new position or adjusting the start and end points.The same vocal recording after processing with the Crossfade function technique described in the main text. Where necessary, the crossfades may be fine tuned directly in the Project window by dragging the whole crossfade to a new position or adjusting the start and end points.Here, the Crossfade function is used in an unorthodox manner to create a 'bowl'-shaped envelope, a non-destructive alternative to the Fade-out, Silence and Fade-in functions in one easy move. This is invaluable for reducing lip noise and interference between words and phrases in vocal takes.Here, the Crossfade function is used in an unorthodox manner to create a 'bowl'-shaped envelope, a non-destructive alternative to the Fade-out, Silence and Fade-in functions in one easy move. This is invaluable for reducing lip noise and interference between words and phrases in vocal takes.Click removal in the Sample Editor using the Draw tool.Click removal in the Sample Editor using the Draw tool.The next two items on the list, Split At Cursor combined with the Crossfade function, are my secret weapon. I only ever use the former Fade-out, Silence and Fade-in functions for detailed edits where a crossfade fails to achieve a satisfactory result. The real secret here is how you set up the Crossfade dialogue to achieve the same processing action as the former three functions combined. It's relatively easy. Firstly, double-click on an existing crossfade to open the Crossfade dialogue and create your own custom shaped curves or use the preset shape buttons. The idea is to create an overall 'bowl' shaped curve which begins with a fade-out, continues with a short segment of silence (or near silence), and ends with a fade-in. This is a recreation of the Fade-out, Silence and Fade-in functions but it's achieved in one easy move and is entirely non-destructive. For the purposes of this exercise the fades in and out are comparatively short compared to the middle silent section. In addition, the silent section need not be located at the absolute lowest point of the curve display. You may prefer a near-silent horizontal line located just above the lowest point of the curve display. Try a crossfade with an overall duration of around 500-700ms.

To use the Crossfade function in this context, adjust the settings in the Crossfade dialogue to resemble a bowl shaped envelope (as described above). Now select and listen to your audio event (preferably a vocal take or speech). Whenever you hear any unwanted noise in between words or phrases use Split at Cursor (Alt+X) to split the event at that point, in much the same way as you might use markers to mark points of interest. When you have worked through enough audio, select all the newly split events and select Crossfade ('X') to implement crossfades at all the split points.

De-select all the events and audition the crossfades one by one. Many of the crossfades may have already masked the problems within the audio using the default settings but, where necessary, you can fine-tune the results by dragging the curve or changing its length directly in the Project window while auditioning the audio in cycle playback mode. De-activate the Snap button for dragging by small amounts. You may also need to re-open the Crossfade dialogue to fine-tune the curve shapes. Use Locate Next Event and Locate Previous Event ('N' and 'B' key commands) to navigate to each crossfade and try setting up a pre-roll of one or two bars to give yourself a short run-in.

I mostly use this to reduce low-level lip noise and interference in between words and phrases in vocal takes. To make my edits I need to split the events fairly accurately. Each split point falls roughly at the mid-point of each section of unwanted interference. You can go on to create any number of shapes/durations for specific editing tasks and store them in the Crossfade dialogue's preset menu for future use. The default settings of the Crossfade function (stored using the save default button) are recalled whenever you open the dialogue. This is handy for repetitive tasks.

Click Removal

The final two items in the first table are designed specifically for click removal using the Draw tool in the Sample Editor. Normally, when you open the Sample Editor after having made a selection with the Range Selection tool, the editor opens focused upon the entire event within which you made your selection. Since this is not always convenient, I have created a Macro which forces the Sample Editor to open focused precisely upon the current range selection (see the table below for a list of the functions contained within this Macro, and see Mark Wherry's article on Macros in the July 2003 issue of SOS for more details about creating your own Macros).

Macro: Open Focused Sample Editor

Transport — Locators To Selection

Edit — Open

Zoom — Zoom To Locators

Edit — Select In loop

Zoom — Zoom To Selection

To understand how the focused Sample Editor macro can help you, try the following: choose your audio containing the click or other irregularity. While remaining in the Project window, zoom in closely and select a small zone around the click using combinations of the first five tools/functions in the first table. You will normally need to deactivate the Snap button for this kind of work.

When you feel ready to make the edit, use the focused Sample Editor macro. This procedure is often quicker than opening a non-focused Sample Editor and, more often than not, helps you get to the problem area with greater ease (I should also mention that the Open Focused Sample Editor macro may also be used to good effect on MIDI parts). Once you are in the Sample Editor, you may need to zoom in still more by dragging downwards with the pointer in the ruler. The zoom factor must be less than one before you can use the Draw tool. The zoom factor is shown in the info bar, and you will know that it is less than one when the waveform is shown as a line rather than as a 'filled' form. Your click should now be clearly visible in the display and may resemble the one shown in the screenshot below. To remove the click, select the Draw tool and manually re-draw a line over the appropriate range, attempting to create a plausible waveform according to the surrounding characteristics. If you are good at drawing you should now be click-free!

Clarification

To clarify your understanding of the techniques described above, just remember that each procedure involves two overall logical stages: 'selecting' followed by 'editing'. With reference to the list of tools/functions in the first table, the first five items are for selecting, and the next seven are for editing. Easy! 

Published September 2006